Rotary filter or strainer



Aug. 5, 1924. 1,504,020

F. W. BRACKETT ROTARY FILTER OR STRAINER Filed Sept. 6. 1923 2 Sheets-Sheet l by @//y Aug, 5', 1924.

F. BRACKETT ROTARY FILTER OR STRAINER Filed Sept. 6,

1923 2 Sheets-Sheet 2 Patented Aug. 5, 1924'.

.PA'EEN'E WHITWELL BBACKETT, Oll COLCHESTER, ENGLAND.

Appueatien med september c, laas. serial ne. camel.

To all 'whom t may concern:

Be it known that I, FRANCIS WHrrwELL BRAoKE'rr, a subject of the King of Great Britain, residing in Colchester, England, have invented certain new and useful Improvements Relating to Rotary Filters or Strainers, iication.

This invention relates to rotary apparatus used for effecting the filtering or straining` of liquids in two or more sta es, the ape' paratus being of the kind wherein the liquid is caused while passing from an inlet to an outlet to flow in turn through a series of concentric rotating drum screens. It

consists in an improved construction and arrangement of parts as .hereinafter die- Scribed and claimed.

The improved apparatus is particularly suitedfor dealing with Wash Water used for quenching coke in coke oven installations and separating from the water the small pieces of coke and coke-dust which is contained in considerable quantities in such water, thereby rendering it-clean, and recovering the coke which would otherwise be wasted. To this end each drum screen may be provided, as the sieve portions in some lknown types of rotary drum. lters have been, with means whereby solids retained by the screens are raised by means of scoops attached to the inside of the drum screens and yadapted to deliver .the solids when` raised into discharging trou hs, the screens.

being cleansed'by means o projected `against them. y The accompanying Adrawings show a ro# tary coke screening apparatus constructed and arranged according to the invention and in its simplest form comprising two screens, Fig. 1 being a vertical section thereof, and Fig. 2 an end elevation. i

The illustrated apparatus consists oir a hollow open-ended horizontal cylinder 1 closed at one end by a plate 2, the cylinder bein mounted on a shaft v3 carried "in suita le bearings 4 supported in any suit'- able manner, as for instance by girders 21.

The periphery of the cylinder may be formed oi ne wire gauze or 4the like 5 which constitutes one of the screens. Concentrically disposed` inside this cylinder is a small open-ended hollow cylinder 6 whose periphery, constitutingthe other or 'coarser screen, or the rst. stage, may beof perof which the following is a speci-A forated plate `7. The two cylinders or `screens form between them j'an annularshown, anelectric motor 9 and multiworm reduction gears 10. A

The drum is arrangedwith its lower portion dipping into a tank 11, which 'is ere shown made of metal, but may, if preferred, be madel of brick, concrete or the like. The level of* the water or li uid in the tank (indicated ap roximately' y. the line 12), is above thein et 24 in one ofthe side walls of the tank 1l, through which inlet the uncleaned water ory liquid to be cleaned is admitted to the tank l1 and then` to the inner cylinder through the open end 25 'of the latter.

ln carrying out a water-iltering or straining peration, the uncleaned water or liquid is delivered to the tank 11 at one side of the latter through the supply duct 24 and then to the interlor of the inner cylinder 6. Owing tothe head of water, the Water Hows, as indicated by the arrows in Fig. 1, rst through the perforated plate 7 constituting the periphery of the inner cylinder, thenthrough the wire gauze 5 constituting the periphery of the outer cylinder 1, and then into the tank or sump 11 from whence it passes out throu h an outlet or' over-fiow 13 provided for t e purpose at the opposite side of the tank 11. l'lncleanedl water may be prevented .from passing round 'the outside of the drum and be compeiled to pass only throu h the straining screens or cylinder rims y means of sealing strips, arranged between the walls of the tank and the drums. rihese sealing strips may, conveniently, consist of flat pieces of rubber 14 curv to,lie on suitable curved supports i5 of substantially the same radius as the peripheral Jiaces oi the screens, the strips 14 being arranged to be in close vicinity to those faces or to similar strips 14 carried bythe screens.

@wing to the fiow of the water through the strainer or drum the larger pieces of coke are caught upon the inner surface of the inner or coarser screen 7, the finer p ieces passing through this screen being caug t by the outer or nner screen 5.

Paddles or scoops 16 and i7 may be fitted around the inner surfaces of the two respective screens for the purpese as extiti lili) dil@ plained above for lifting pieces caught by the screens, the scoops being arranged radially or nearly Iso, their outer ends being open and adjacent to the surfaces o the screens,lso that water lifted by the scoops can drain away through the screens.

On the strainer being slowly rotated, the

fouled portions of the perforated plate .7 of

the inner .cylinder 6 vand of the wire gauze 5 of the outer cylinderl are drawn out of the 'water with the smaller coke adhering to them. The larger pieces of cokewhi'ch` are too bigito cling to the gauze 5 and plate 7 areelevated', respectively,- by means of lthe'paddles 16 Aand 17,' until they reach the point immediately below two superposed series of cleaning jets 18 and 19, through which high pressure water is sprayed on to and through the external portion of the vouter and inner cylinders, depositing the out of the scoops 16 and 17 on to the inner,

screen before the scoops arrive in succession above the troughs 20, spring trap plates 22, 23, maybe attached to the troughs and arranged to bear against the lips of the scoops and thereby prevent the pieces of cok'e 'falling on to the screen as the scoops move into the Vicinity of the troughs, as shown rin he screened materials can be removed from the' trough or troughs by any appropriate means.`

` Having thus described the nature oi the said invention and the best means l know of carrying the same into practical edect, l claim:

1. ln a rotary liquid filter or strainer of .the class described, a tank having on one side an inlet opening whereby unstrained liquid enters the tank and in al second side an outlet for 'the liquid after straining, a horizontal rotatably-mounted power shaft `of cokespanning the tank, a series of horizontally disposed cylindrical screens forming drums having openends adjacent to the inlet side of the tank and closed ends adjacent to the outlet side ofthe tank, said screens being secured to the said shaft and disposed `in concentric relation one within another and each with -a portion dipping into theitank, each screen being' composed of foraminous material, the size of the openings insuccessive screens being respectively diminished in a manner to render the screens sucdesysively finer. from the innermost to the outer-l most screen of the series, and means, consisting of annular sealing strips interposed between the walls of the tank and the outer peripheral surfaces of the screens, to pre- 1 vent unstrained liquid which entersthe tank through its inlet from passing from the inlet sideof the tank to the outlet side `thereof between the side walls and the circumferential marginal edges ofthe screens, the liquid entering the innermost cylindrical screen being causedto pass in succession through the concentric cylindrical screens to the outlet side of the tank,"substantially as described. f

2. ln afrotary liquid filter or strainer according to claim 1, means carried by each screen for elevating solid matter, said means consisting of radially arranged scoops lsecured to vtheA inner surfaces of the screens` the ends of the scoops adjacent the said surfaces being open. f

'3. ln a'rotaryliquld filter or strainer according to clalm l, a plurality of scoops,

carried by the inner surface of each of said screens and extending toward the axistherej of r elevating coarse materlal, meansV com-- prising a plurality o setsof waterspray y nozzles-for cleaning the inner surfaces of the concentric screens, a -seto'f said nozzles being arranged externally of and in prox-y imity to the outer surface of each of said screens, ard means, consisting of a plurality of troughs, for therec'eption of the spray Water and solid material delivered by said scoops, one of said troughs being arranged` yinternally of each screen and in opposing relation vto each of said nozzles, substantially as described., l i

In testimony `whereof i have signed my name to this specification. v FRANClS Wiil'iwlil.. BRAtitl-ZTT. 

